Aligned carbon nanotubes have application in numerous areas of composite materials, such as for use in separation media, as catalysts, as catalyst supports, in energy storage and transfer, in electronics applications such as in electron guns for use, e.g., in flat panel television picture technology, for EMI and RF shielding such as in the cellular telephone industry, as sensors or sensor components, and for use in electronically conductive plastics. Currently utilized technologies for production of aligned carbon nanotubes are labor intensive, costly, inefficient, and are not amenable to scale-up for industrial applicability.
The synthesis of aligned carbon nanotubes, such as multi-walled carbon nanotubes, via catalytic pyrolysis of hydrocarbons is known. Most of the known methodology for such synthesis requires use of patterned or preformed substrates to provide support to the growing nanotubes, allowing growth in an aligned pattern. Further, the presently utilized methods for synthesis of aligned carbon nanotubes rely on batch processes. While effective, batch processing methods for production of carbon nanotubes, particularly aligned carbon nanotubes, are labor intensive, costly, inefficient, and generally limited in production capacity at the industrial scale. Further, batch processing techniques may result in significant batch to batch variation in the quality of the nanotubes produced.
Accordingly, there is a need in the art for methods of production of carbon nanotubes which result in a high quality, homogenous population of aligned nanotubes. There is further a need in the art for such methods, and for apparati for conducting the methods, which do not require specialized patterned substrates. The methods should reduce the labor required, and be amenable to scale-up for use in industrial applications requiring reproducibility, low cost, high volume, and a high quality product.